Summary: ANIMAL BEHAVIOUR, 2001, 62, 635642
doi:10.1006/anbe.2001.1794, available online at http://www.idealibrary.com on
Division of labour within teams of New World and Old World
NIGEL R. FRANKS*, ANA B. SENDOVA-FRANKS & CARL ANDERSON
*School of Biological Sciences, University of Bristol
Faculty of Computer Studies and Mathematics, University of the West of England
LS Biologie I, Universitašt Regensburg
(Received 7 February 2001; initial acceptance 5 April 2001;
final acceptance 28 May 2001; MS. number: 6827R)
In army ants, prey items are often retrieved by cooperative teams of workers rather than by single porters.
We used experiments and randomization tests to explore the division of labour within such teams in the
New World army ant Eciton burchelli, and the Old World army ant Dorylus wilverthi. We evaluated these
teams in the light of a recent proposal that teams should be defined in terms of the concurrent
performance of different subtasks by their members. This is a broader and more useful definition of teams
than a previous one in which teams were defined by a membership necessarily involving different castes.
Within army ant teams there is a front runner who initiates prey retrieval and one or more followers.
Hence, there are two qualitatively different subtasks that must be performed concurrently during such
teamwork. Previous work has shown that these teams are superefficient: the combined weight of the prey
retrieved by the team is greater than the sum of the maximum weights the team members could carry